Difference between implementing RAID 0 and attaching multiple EBS Volumes on AWS

Question

What is difference between implementing RAID 0 and just attaching multiple EBS Volumes on AWS EC2? Both seem to just sum the performance (?). Any other operational differences or use case scenarios, even cost - RAID-0 vs Single Volume.

Answer 1

You can certainly create a RAID with EBS. AWS Actually has a guide on how to configure RAID 0 (which is the recommended one) with 2 or more EBS volumes.

RAID 0 arrays on Amazon EBS boost file system performance by spreading I/O across multiple volumes. They're best for high-performance needs. Adding volumes increases throughput and IOPS, but performance is limited by the slowest volume, and losing any volume means losing all data. The array's size and bandwidth are the combined sizes and bandwidths of its volumes. For example, two 500 GiB io1 volumes with 4,000 IOPS each form a 1000 GiB RAID 0 array with 8,000 IOPS and 1,000 MiB/s throughput.

To prevent catastrophic data loss, it is recommended to backup your RAID volumes with EBS multi-volume snapshots

Answer 2

Adding multiple EBS volumes on EC2 without creating a RAID does not "sum" the performance. With individual volumes simply mapped to separate mount points, you would only get the performance of a single volume (the volume mounted to the path you are writing to) during any write operation.

Answer 3

Both RAID are increase storage performance. But there are some key differences and considerations to keep in mind:

RAID 0:

1. Utilizes data striping for improved performance. It means, this can improve read and write performance since multiple disks can work in parallel to retrieve or store data.
2. No fault tolerance. It means, if one disk fails, all data stored across the entire array may be lost.
3. It Requires configuration. This involves additional management overhead.
4. No additional cost beyond disks.

Attaching Multiple EBS Volumes:

1. There is No striping. Each volume operates independently.
2. No fault tolerance across volumes. Isolated failures.
3. Simple attachment, and possible managed through AWS tools easily.
4. Incurs additional cost per volume.

Use Case:

RAID 0: Where performance is critical and fault tolerance is not a concern, such as high-performance computing, data analytics, and temporary data storage where data integrity is not crucial.

Attaching Multiple EBS Volumes: Where fault tolerance is important, or when you need to scale storage capacity without necessarily maximising performance, such as web servers, databases, and file servers.